Generally, an air conditioner is a device for cooling or heating an indoor space by performing compression, condensation, expansion and evaporation of a refrigerant. And, the air conditioners are classified into a normal air conditioner including an outdoor unit and an indoor unit connected to the outdoor unit and a multi-type air conditioner including an outdoor unit and a plurality of indoor units connected to the outdoor unit. Moreover, the air conditioners are classified into a cooling air conditioner supplying a cool air only to an indoor space by driving a refrigerant cycle in one direction only and a cooling and heating air conditioner supplying a cool or hot air to an indoor space by driving a refrigerant cycle selectively and bi-directionally.
A configuration of an air conditioner according to a related art is explained with reference to FIG. 1 as follows.
FIG. 1 is a block diagram of an air conditioner according to a related art.
Referring to FIG. 1, an air conditioner according to a related art basically consists of a compressor 10, a condenser 30, an expansion valve 40, an evaporator 60, and a 4-way valve 20 to configure a cooling cycle. And, the respective elements of the related art air conditioner are connected to one another via a connecting pipe 70 playing a role as a passage for a refrigerant.
A process for operating the above-configured air-conditioning system to cool down an indoor space is explained according to a refrigerant flow as follows.
First of all, the gaseous refrigerant having exchanged heat with an indoor air in the evaporator 60 is introduced into the compressor 10. The gaseous refrigerant introduced into the compressor 10 is compressed at high temperature and pressure by the compressor 10.
Subsequently, the compressed gaseous refrigerant is introduced into the condenser 30 to undergo a phase change into a liquid refrigerant. In particular, the refrigerant changes its phase in the condenser 30 to emit heat externally.
The refrigerant discharged from the condenser 30 expands via the expansion valve 40 and is then introduced into the evaporator 60.
The liquid refrigerant introduced into the evaporator 60 changes its phase into a gaseous refrigerant. In doing so, the phase-changing refrigerant absorbs external heat to cool an indoor space.
Besides, in order to heat the indoor space, a flow of the refrigerant is switched by the 4-way valve 20 to operate the cooling cycle in a reverse direction.